Characteristics: Macbeth is noble and brave in the beginning of the play. He is rewarded by King Duncan for "unseeming a man from the nave to the chops" in battle, so he is certainly not unfamiliar with killing. However, as someone who is noble, Macbeth's virtue is not at ease with murder. Lady Macbeth says he has ambition, but lacks the "illness" that must attend it, suggesting he lacks a kind of selfish, Machiavellian ambition that she feels is necessary for forcing the fate told to him by the witches into fruition. She is certainly more power hungry than Macbeth. She is unphased by the bloody scene left after Macbeth kills Duncan, as seen by her callous words suggesting that looking at the dead body is no different than looking on a painting, or someone asleep. He is so disturbed he refuses to return the daggers. She confidently returns them herself. Macbeth returns saying that the blood on his hands could turn the entire sea incarnadine, but Lady Macbeth says "a little water will cure us of this deed" showing her insouciant attitude toward Duncan's murder. Unfortunately though, Macbeth grows accustomed to killing as he willingly says he'll kill Macduff's family himself, and right away- no hesitation. "Brave Macbeth" returns at the end of the play again, when he chooses to face Macduff man to man, despite the fact he knows he will die.
The purpose of Macbeth and Lady Macbeth is obvious, as is the purpose of Duncan and Malcolm. They are all part of history even though Shakespeare flip-flopped the real perception of those figures with the perception the play gives. Those characters, too, are among the main characters of the play. The three witches, or Weird Sisters, of the play have a different purpose. People in Shakespeare's time and before were much more prone to believe in beings with magical powers than are people today. King James I believed very much in the existence of such beings. He was convinced that witches had tried to kill him. He wrote a piece called "Daemonologie" in which he tried to convince people to take witchcraft seriously. Shakespeare, in his attempt to get in the good graces of the newly crowned king who followed Queen Elizabeth I, a major supporter of the theater, wrote the witches into the play. Their purpose in the play also is integral in that they are the ones who nourish the seed of ambition that they know already is in Macbeth. Later, they make him feel supremely confident of his infallibillity by showing him three visions that give him false hope. They take advantage of Macbeth's weaknesses very successfully. They are evil which aligned with the beliefs of King James I.